Blade rotation angle on energy performance and tip leakage vortex in a mixed flow pump as turbine at pump mode

Liu, Yabin; Han, Yadong; Tan, Lei; Wang, Yuming

doi:10.1016/j.energy.2020.118084

Cited by 46 publications

(18 citation statements)

References 34 publications

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“…Cui et al [21] found that the suitable cutting of the blade tailing angle can improve the hydraulic performance, unstable flow, and vibration of the centrifugal pump. Liu et al [22] found that with an increase in the blade rotation angle, the best efficiency point shifts toward a large flow condition under the pump mode and turbine mode; the authors also analyzed the evolution of the tip leakage vortex when the blade rotation angles are 4°and −4°. Peng et al [23] showed that increasing the blade outlet angle pair reduces the cavitation performance of a multistage submersible pump with a low specific speed and increase the flow separation of the blade working surface.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation and Experiment of the Effects of Blade Angle Deviation on the Hydraulic Characteristics and Pressure Pulsation of an Axial‐Flow Pump

Shi

Zhu

Yuan

et al. 2021

Shock and Vibration

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Inadequate blade angle adjustment or manufacturing errors will cause inconsistencies in the blade angle of an axial-flow pump. In this study, the hydrodynamic characteristics of an axial-flow pump with inconsistent blade angle are investigated by analyzing hydraulic performance and pressure pulsation. The analysis is conducted by performing a numerical simulation combined with a model test. Results show that, relative to the case without blade angle deviation, the case with blade angle deviation exhibits changes in the periodicity of the flow field in the impeller. Such changes result in uneven pressure changes in the impeller passage. The pressure pulsation induced by the blade angle deviation is mainly low-frequency pulsation; that is, it is twice the rotation frequency. The amplitude of the main frequency pulsation is 1.5–3 times that of the blade without angle deviation. This low frequency that dominates the whole pump device easily causes the vibration and weakens the safety and stability of the pump. The blade angle deviation exerts great influence on the unsteady characteristics. Hence, blade angle deviation seriously affects the safe and stable operation of axial-flow pumps and pump stations.

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Section: Introductionmentioning

confidence: 99%

Numerical Simulation and Experiment of the Effects of Blade Angle Deviation on the Hydraulic Characteristics and Pressure Pulsation of an Axial‐Flow Pump

Shi

Zhu

Yuan

et al. 2021

Shock and Vibration

View full text Add to dashboard Cite

show abstract

“…As a resource for sustainable development, green energy has attracted increasing attention from researchers and industries [1][2][3]. Therefore, in recent years, the trend of developing renewable and clean energy has been increasing, with hydropower playing an important role and developing at an unprecedented rate [4][5][6]. Among them, the tubular turbine has the advantages of a short construction period, small investment, large excess flow, high efficiency, good cavitation performance, and fewer blades.…”

Section: Introductionmentioning

confidence: 99%

Effect of Tip Clearance Size on Tubular Turbine Leakage Characteristics

Zhu

2021

Processes

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To study the effect of tip clearance on unsteady flow in a tubular turbine, a full-channel numerical calculation was carried out based on the SST k–ω turbulence model using a power-plant prototype as the research object. Tip leakage flow characteristics of three clearance δ schemes were compared. The results show that the clearance value is directly proportional to the axial velocity, momentum, and flow sum of the leakage flow but inversely proportional to turbulent kinetic energy. At approximately 35–50% of the flow direction, velocity and turbulent kinetic energy of the leakage flow show the trough and peak variation law, respectively. The leakage vortex includes a primary tip leakage vortex (PTLV) and a secondary tip leakage vortex (STLV). Increasing clearance increases the vortex strength of both parts, as the STLV vortex core overlaps Core A of PTLV, and Core B of PTLV becomes the main part of the tip leakage vortex. A “right angle effect” causes flow separation on the pressure side of the tip, and a local low-pressure area subsequently generates a separation vortex. Increasing the gap strengthens the separation vortex, intensifying the flow instability. Tip clearance should therefore be maximally reduced in tubular turbines, barring other considerations.

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“…Many scholars used numerical simulation and test measurement (high-speed photography and particle image velocimetry) to study the TLV in axial flow pump [7], mixed flow pump [8], pump jet [9,10], and multiphase pump [11]. The research found that the evolution of TLV includes splitting stage, developing stage and merging stage [12]. The cavitation pattern induced by TLV consists of TLV cavitation, tip corner vortex cavitation, shear layer cavitation, jetting shear layer cavitation, and suction-side-perpendicular cavitating vortices [13,14].…”

Section: Introductionmentioning

confidence: 99%

Energy Characteristics of Full Tubular Pump Device with Different Backflow Clearances Based on Entropy Production

Meng

Pei

2021

Applied Sciences

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In this study, the entropy theory was used as the evaluation standard of energy dissipation, and the effect of backflow clearance (the gap between motor rotor and motor shell) on energy characteristics of a full tubular pump was investigated by 3D unsteady flow simulation. The calculated results validated through testing shows that backflow clearance produces additional head loss and the rotation of the motor rotor requires more shaft power. The additional energy losses lead to a significant decline in the efficiency of tubular pump device. Under design conditions, the total dissipation of backflow clearance, rear guide vane, and outlet passage decreases with the increase of clearance radius, but that of the impeller decreases first and then rises with the increase of clearance radius. In addition, the increase of the clearance radius leads to disorderly flow pattern in the impeller. The total dissipation rate on the impeller suction side and near the impeller inlet increases with the increase of backflow clearance radius, but that on the impeller suction side decreases with the increase of backflow clearance radius. The total dissipation rate of the suction side of the guide vane and the wall of the outlet passage decreases with the increase of backflow clearance radius. This work can provide an intuitive analysis of the energy dissipation caused by backflow clearance and reference for engineering applications of full tubular pump.

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Blade rotation angle on energy performance and tip leakage vortex in a mixed flow pump as turbine at pump mode

Cited by 46 publications

References 34 publications

Numerical Simulation and Experiment of the Effects of Blade Angle Deviation on the Hydraulic Characteristics and Pressure Pulsation of an Axial‐Flow Pump

Numerical Simulation and Experiment of the Effects of Blade Angle Deviation on the Hydraulic Characteristics and Pressure Pulsation of an Axial‐Flow Pump

Effect of Tip Clearance Size on Tubular Turbine Leakage Characteristics

Energy Characteristics of Full Tubular Pump Device with Different Backflow Clearances Based on Entropy Production

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